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Fluid storage, disposal and reuse

We take a responsible approach to the sourcing, use, transport and disposal of water.

Various fluids are used throughout our operations, including drilling and hydraulic fracturing. Proper storage, handling and disposal of these fluids are important in preventing contamination of shallow groundwater. Effectively managing fluid storage and disposal allows us to significantly reduce the potential of the environment being impacted by a surface release of the fluids we use.

How does Encana store drilling, fracturing and flowback fluids?

Our approach to storing fluids varies, depending on the location and requirements of each well. In most of our operations, we use closed-loop fluid handling systems. These systems keep drilling and hydraulic fracturing fluids within a series of pipes and tanks throughout the entire fluid storage process. Because drilling and fracturing fluids do not come into contact with the ground surface, there is less likelihood of groundwater contamination.

In some areas, we use conventional pits to hold drilling fluids and waste. These pits can be excavated holes in the ground or steel tanks found above ground. For pits constructed using ground excavation, we line the pits to prevent fluids from migrating into the ground. The storage and handling of waste is regulated in all the areas where we operate.

How does Encana dispose of flowback fluids?

Following hydraulic fracturing operations, fluids that return to the surface are referred to as flowback. In addition to the original hydraulic fracturing fluids used, flowback can also contain water which was once housed in the rock formation. Water that is produced from the formation after the gas well is put on production is called produced water. Typically, produced water has a high salt content and is not suitable for domestic or livestock use.

Where we are unable to reuse produced water and flowback fluids, we dispose of these substances responsibly in order to avoid the contamination of freshwater resources or land. In most cases, unusable and/or excess flowback water is transported and disposed of in licensed oil field disposal wells through a process called deep-well injection. Regular inspections and tests are conducted on disposal wells throughout the life of the well to ensure mechanical integrity and containment. We may also dispose of water at industrial disposal facilities in compliance with applicable state and provincial regulations.

Does Encana reuse fluids?

We actively seek opportunities to reuse water and fluids in our operations wherever practical and allowed by regulation. For example, in Colorado’s Piceance Basin, we have facilities in four locations designed to treat about 5,300 cubic metres (45,000 barrels) per day and reuse produced water. Produced water from our wells and flowback water from well hydraulic fracturing operations is transported to these facilities by an extensive network of pipelines. We also reuse drilling fluid. After a well is drilled, drilling fluid can be recovered and transported to a specialized plant, where it is processed, stored and reused at future drill sites.

Disclosure

We are committed to continuously improving the methods and measures of our performance.

We are actively encouraging our suppliers to continue to improve their disclosure of hydraulic fracturing fluid formulations. We also encourage fluid suppliers to advance the development of more environmentally responsible fluid additives and are continuing to build on our detailed understanding of the products used in hydraulic fracturing.

Through our involvement in industry-leading initiatives like our Responsible Products Program, we are continually working towards improving our disclosure company-wide. Our U.S. subsidiary is also voluntarily disclosing fluid components used in U.S. hydraulic fracturing operations online at FracFocus.org (a joint project of the Ground Water Protection Council and the Interstate Oil and Gas Compact Commission) and we look forward to participating in the newly announced Canadian version of FracFocus.